Dynamic resolution of fully qualified domain name (FQDN) address objects in policy definitions

ABSTRACT

Dynamic resolution of Fully Qualified Domain Name (FQDN) address objects in policy definitions is provided. In some embodiments, dynamic resolution of Fully Qualified Domain Name (FQDN) address objects in policy definitions includes receiving a network policy that includes a domain name (e.g., the network policy can include a network security rule that is based on the domain name); and periodically updating Internet Protocol (IP) address information associated with the domain name by performing a Domain Name Server (DNS) query. In some embodiments, dynamic resolution of Fully Qualified Domain Name (FQDN) address objects in policy definitions includes dynamically performing a first local Domain Name Server (DNS) lookup for a first VSYS using a first DNS server on a first domain name for implementing a network policy based on the first domain name; dynamically performing a second local DNS lookup for a second VSYS using a second DNS server on the first domain name for implementing the network policy based on the first domain name; in which the network policy includes a network security rule that is based on the first domain name, and the network policy includes a network security rule that is based on the second domain name.

CROSS REFERENCE TO OTHER APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 13/115,894, entitled DYNAMIC RESOLUTION OF FULLY QUALIFIEDDOMAIN NAME (FQDN) ADDRESS OBJECTS IN POLICY DEFINITIONS filed May 25,2011 which is incorporated herein by reference for all purposes.

BACKGROUND OF THE INVENTION

A firewall generally protects networks from unauthorized access whilepermitting authorized communications to pass through the firewall. Afirewall is typically a device or a set of devices, or software executedon a device, such as a computer, that provides a firewall function fornetwork access. For example, firewalls can be integrated into operatingsystems of devices (e.g., computers, smart phones, or other types ofnetwork communication capable devices). Firewalls can also be integratedinto or executed as software on computer servers, gateways,network/routing devices (e.g., network routers), or data appliances(e.g., security appliances or other types of special purposes devices).

Firewalls typically deny or permit network transmission based on a setof rules. These sets of rules are often referred to as policies. Forexample, a firewall can filter inbound traffic by applying a set ofrules or policies. A firewall can also filter outbound traffic byapplying a set of rules or policies. Firewalls can also be capable ofperforming basic routing functions.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings.

FIG. 1 is a functional diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments.

FIG. 2 is a block diagram of a network for dynamic resolution of FQDNaddress objects in policy definitions in accordance with someembodiments.

FIG. 3 is another block diagram of a network including virtual systems(VSYS) for dynamic resolution of FQDN address objects in policydefinitions in accordance with some embodiments.

FIG. 4 is a block diagram illustrating an architecture for dynamicresolution of FQDN address objects in policy definitions in accordancewith some embodiments.

FIG. 5 is a functional diagram of hardware components of a dataappliance for dynamic resolution of FQDN address objects in policydefinitions in accordance with some embodiments.

FIG. 6 is a functional diagram of logical components of a data appliancefor dynamic resolution of FQDN address objects in policy definitions inaccordance with some embodiments.

FIG. 7 is a flow diagram for dynamic resolution of FQDN address objectsin policy definitions in accordance with some embodiments.

FIG. 8 is another flow diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments.

FIG. 9 is another flow diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments.

FIG. 10 is another flow diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments.

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term ‘processor’refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

A firewall generally protects networks from unauthorized access whilepermitting authorized communications to pass through the firewall. Afirewall is typically a device, a set of devices, or software executedon a device that provides a firewall function for network access. Forexample, a firewall can be integrated into operating systems of devices(e.g., computers, smart phones, or other types of network communicationcapable devices). A firewall can also be integrated into or executed assoftware applications on various types of devices, such as computerservers, gateways, network/routing devices (e.g., network routers), ordata appliances (e.g., security appliances or other types of specialpurposes devices).

Firewalls typically deny or permit network transmission based on a setof rules. These sets of rules are often referred to as policies (e.g.,network policies or network security policies). For example, a firewallcan filter inbound traffic by applying a set of rules or policies toprevent unwanted outside traffic from reaching protected devices. Afirewall can also filter outbound traffic by applying a set of rules orpolicies (e.g., allow, block, monitor, notify or log, and/or otheractions can be specified in firewall rules or firewall policies, whichcan be triggered based on various criteria, such as described herein).

Security appliances or gateway appliances can include security functions(e.g., firewall, anti-malware, and intrusion prevention/detection,and/or other security functions), networking functions (e.g., routing,Quality of Service (QoS), workload balancing of network relatedresources, and/or other networking functions), and/or other functions.For example, routing functions can be based on source information (e.g.,IP address and port), destination information (e.g., IP address andport), and protocol information.

A basic packet filtering firewall filters network communication trafficby inspecting individual packets transmitted over a network (e.g.,packet filtering firewalls or first generation firewalls, which arestateless packet filtering firewalls). Stateless packet filteringfirewalls typically inspect the individual packets themselves and applyrules based on the inspected packets (e.g., using a combination of apacket's source and destination address information, protocolinformation, and a port number).

Application firewalls can also perform application layer filtering(e.g., application layer filtering firewalls or second generationfirewalls, which work on the application level of the TCP/IP stack).Application layer filtering firewalls or application firewalls cangenerally identify certain applications and protocols (e.g., webbrowsing using Hyper Text Transfer Protocol (HTTP), a Domain Name System(DNS) request, a file transfer using File Transfer Protocol (FTP), andvarious other types of applications and other protocols, such as Telnet,DHCP, TCP, UDP, and TFTP (GSS)). For example, application firewalls canblock unauthorized protocols that attempt to communicate over a standardport (e.g., an unauthorized/out of policy protocol attempting to sneakthrough by using a non-standard port for that protocol can generally beidentified using application firewalls).

Stateful firewalls can also perform stateful based packet inspection inwhich each packet is examined within the context of a series of packetsassociated with that network transmission's flow of packets/packet flow(e.g., stateful firewalls or third generation firewalls). This firewalltechnique is generally referred to as a stateful packet inspection as itmaintains records of all connections passing through the firewall and isable to determine whether a packet is the start of a new connection, apart of an existing connection, or is an invalid packet. For example,the state of a connection can itself be one of the criteria thattriggers a rule within a policy.

Advanced or next generation firewalls can perform stateless and statefulpacket filtering and application layer filtering as discussed above.Next generation firewalls can also perform additional firewalltechniques. For example, certain newer firewalls sometimes referred toas advanced or next generation firewalls can also identify users andcontent (e.g., next generation firewalls). In particular, certain nextgeneration firewalls are expanding the list of applications that thesefirewalls can automatically identify to thousands of applications.Examples of such next generation firewalls are commercially availablefrom Palo Alto Networks, Inc. (e.g., Palo Alto Networks' PA Seriesfirewalls). For example, Palo Alto Networks' next generation firewallsenable enterprises to identify and control applications, users, andcontent—not just ports, IP addresses, and packets—using variousidentification technologies, such as the following: APP-ID for accurateapplication identification, User-ID for user identification (e.g., byuser or user group), and Content-ID for real-time content scanning(e.g., controls web surfing and limits data and file transfers). Theseidentification technologies allow enterprises to securely enableapplication usage using business-relevant concepts, instead of followingthe traditional approach offered by traditional port-blocking firewalls.Also, special purpose hardware for next generation firewallsimplemented, for example, as dedicated appliances generally providehigher performance levels for application inspection than softwareexecuted on general purpose hardware (e.g., such as security appliancesprovided by Palo Alto Networks, Inc., which utilize dedicated, functionspecific processing that is tightly integrated with a single-passsoftware engine to maximize network throughput while minimizinglatency).

A network policy typically uses various combinations of source anddestination addresses, subnets, and ports to apply a policy. However,there are many use cases in which, rather than using IP addresses, it ismore convenient and logical for the network policy to be defined byFully Qualified Domain Names (FQDNs) (e.g., www.yahoo.com orwww.google.com). In some cases, rather than using IP addresses, it ismore convenient and logical for the network policy to be defined byspecific server names (e.g., MailServer), which can be resolved by acentral and/or local DNS and applied to multiple devices. Specifically,each device can resolve these names to various IP addresses based onvarious network configurations and device deployments. For example,MailServer can resolve to different IP addresses at various remote siteoffices of a single enterprise. Similarly, the same policy specified bya FQDN can be applied to multiple virtual systems, and each virtualsystem can resolve the names to its range of IP addresses. These andother examples are discussed in greater detail below with respect toFIG. 3.

Certain network policies can include domain names. However, such networkpolicies generally only perform the Domain Name Server (DNS) lookup toresolve the domain names when the network policy or network policy rulethat includes the domain name is configured (i.e., at configurationtime) and do not dynamically update the associated IP addressinformation. However, IP addresses associated with domain names are notnecessarily static and, as a result, such non-static IP addresses canchange frequently and/or various domains frequently add new IPaddresses, remove old IP addresses, and/or potentially use variousContent Distribution Networks (CDNs) for hosting content. Also, forsecurity policies, frequently resolving domain names can be more secure.Thus, current approaches do not provide for dynamic resolution (e.g.,and thus may not have current IP address information for the domainname) for effective policy enforcement. Also, the current approaches donot address usage for virtual system (VSYS) environments.

What are needed are improved techniques for using network policies thatare specified using Fully Qualified Domain Names (FQDNs), such as fornetwork policy enforcement and/or security policy enforcement.

Accordingly, dynamic resolution of FQDN address objects in policydefinitions (e.g., network policies) is provided. In some embodiments,dynamic resolution of FQDN address objects in policy definitionsincludes receiving a network policy that includes a domain name (e.g.,the network policy can include a network security rule that is based onthe domain name); and periodically updating Internet Protocol (IP)address information associated with the domain name by performing aDomain Name Server (DNS) query.

For example, using this approach that supports the use of specifyingnetwork policies based on FQDN address objects can improve the workflowfor security policy management. This approach can also improveeffectiveness of policy enforcement by dynamically resolving the domainnames and periodically updating the resolved IP addresses to maintainfreshness of the resolved IP addresses. This approach can also improvemonitoring of events by providing context sensitive resolution of IPaddresses to names (e.g., domain names and/or host/server names). Also,using the various techniques described herein, the resolution of theFQDN address objects need not only be performed at configuration time,and can also be performed dynamically (e.g., at enforcement time) andupdated as necessary for policy enforcement. The techniques describedherein can also support both Internet Protocol version 4 (IPv4)addresses and Internet Protocol version 6 (IPv6) addresses.

In some embodiments, the system includes a security appliance (e.g., thesecurity appliance can include a firewall). In some embodiments, the IPaddress information includes Internet Protocol Version 4 (IPv4)information or Internet Protocol Version 6 (IPv6) information, and thedomain name includes a Fully Qualified Domain Name (FQDN).

In some embodiments, the IP address information is periodically updatedbased on a Time To Live (TTL) value. In some embodiments, the IP addressinformation is periodically updated based on a system frequency. In someembodiments, the IP address information is periodically updated based ona configuration setting. In some embodiments, the IP address informationis periodically updated based on an event.

In some embodiments, the domain name only includes a subset of a FullyQualified Domain Name (FQDN) (e.g., yahoo or yahoo.com, google orgoogle.com, or facebook or facebook.com), and the policy includes a hostname that is not specified as a FQDN (e.g., MailServer).

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes executing a dynamic resolver, inwhich the dynamic resolver performs the periodically updating the IPaddress information associated with the domain name. In someembodiments, dynamic resolution of FQDN address objects in policydefinitions further includes dynamically performing a resolution of thedomain name (e.g., from central management) for implementing the networkpolicy based on the domain name for enforcing the network policy basedon the domain name, in which the domain name was not necessarilyresolved or updated prior to enforcing the network policy.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes enforcing the network policy basedon the IP address, in which the IP address is associated with the domainname, and the policy includes a rule or action based on the domain name.In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes monitoring events based on a contextsensitive resolution of the domain name.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes storing the domain name, the IPaddress information associated with the domain name, and a Time To Live(TTL) value for the IP address information associated with the domainname (e.g., in a data store including one or more tables).

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes periodically attempting to resolvethe domain name, in which the domain name is unresolved; and disablingor blocking network traffic associated with the unresolved domain namewhile the domain name remains unresolved.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes reporting events based on networksecurity threats, in which the reported events include one or moredomain names associated with at least one of the network securitythreats.

In some embodiments, the various techniques described herein areextended to a centralized policy management as well as to a virtualizedsystem (VSYS) deployment and environment. Accordingly, in someembodiments, dynamic resolution of IP addresses to FQDN address objectson a virtual system (VSYS) basis is provided. In some embodiments,dynamic resolution of FQDN address objects in policy definitionsincludes dynamically performing a first local Domain Name Server (DNS)lookup for a first virtual system (VSYS) using a first DNS server on afirst domain name for implementing a first network policy based on thefirst domain name; dynamically performing a second local DNS lookup fora second VSYS using a second DNS server on the first domain name forimplementing a second network policy based on the first domain name; inwhich the first network policy includes a network security rule that isbased on the first domain name, and the second network policy includes anetwork security rule that is based on the second domain name.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes periodically updating the IP addressinformation associated with the first domain based on a Time To Live(TTL) value, system frequency, a configuration setting, or an event; andperiodically updating the IP address information associated with thesecond domain based on a Time To Live (TTL) value, system frequency, aconfiguration setting, or an event.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes executing a dynamic resolver on asecurity appliance, in which the dynamic resolver periodically resolvesor updates one or more IP addresses associated with each domain nameincluded in the network policy. In some embodiments, dynamic resolutionof FQDN address objects in policy definitions further includes sendingthe resolved domain name information to a second security appliance, inwhich the first security appliance is an active security appliance, andin which the second security appliance is a passive security appliancethat can be used for workload balancing or failover.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions further includes reporting events based on networksecurity threats, in which the reported events include one or moredomain names and one or more VSYS associated with at least one of thenetwork security threats.

FIG. 1 is a functional diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments. Asshown in FIG. 1, network traffic is monitored at a firewall 100. In someembodiments, network traffic is monitored using a data appliance (e.g.,a data appliance that includes security functions, such as a securityappliance that includes a firewall). In some embodiments, networktraffic is monitored using a gateway (e.g., a gateway that includessecurity functions, such as a security gateway). In some embodiments,network traffic is monitored using a host (e.g., security softwareexecuted on a host device, such as a network server or client computingdevice, such as a personal computer, laptop, tablet, or smart phone). Insome embodiments, the network traffic is monitored using pass through(e.g., in line) monitoring techniques. In some embodiments, the networktraffic is collected and/or monitored for events and/or reporting basedon events (e.g., some of the network traffic can be monitored using passthrough techniques and/or some of the network traffic can be collectedand analyzed for monitoring the network traffic offline, such as in logsof network traffic) as further described herein with respect to variousembodiments.

In some embodiments, network traffic is monitored using a state basedfirewall. In some embodiments, the state based firewall can monitortraffic flows using APP-ID engine (e.g., App Signature Check & User IDCheck 108). For example, the monitored network traffic can include HTTPtraffic, FTP traffic, DNS requests, unclassified application traffic(e.g., unknown application traffic), and/or other types of traffic(e.g., traffic using other types of known or unknown protocols).

As shown in FIG. 1, network traffic monitoring begins at 102. An IPaddress and port engine 104 determines an IP address and port number fora monitored traffic flow (e.g., a session) based on packet analysis. Insome embodiments, user identification is then determined (e.g., user IDcan be deduced based on the source IP address). A policy check engine106 determines whether any policies can be applied based on the IPaddress and port number. As also shown in FIG. 1, an applicationsignature check engine 108 identifies an application (e.g., using an APPID engine using various application signatures for identifyingapplications based on packet flow analysis). For example, APP-ID engine108 can be configured to determine what type of traffic the sessioninvolves, such as HTTP traffic, FTP traffic, DNS requests, unknowntraffic, and various other types of traffic, and such classified trafficcan be directed to an appropriate decoder, such as decoders 112, 114,and 116, to decode the classified traffic for each monitored session'straffic flow. If the monitored traffic is encrypted (e.g., encryptedusing SSL, SSH, or another known encryption protocol), then themonitored traffic can be decrypted using a decrypt engine 110 (e.g.,applying man in the middle techniques using a self-signed certificate).A known protocol decoder engine 112 decodes and analyzes traffic flowsusing known protocols (e.g., applying various signatures for the knownprotocol) and reports the monitored traffic analysis to a report andenforce policy engine 120. Identified traffic (no decoding required)engine 114 reports the identified traffic to the report and enforcepolicy engine 120. An unknown protocol decoder engine 116 decodes andanalyzes traffic flows (e.g., applying various heuristics) and reportsthe monitored traffic analysis to the report and enforce policy engine120.

In some embodiments, the results of the various traffic monitoringtechniques using known protocol decoder engine 112, identified trafficengine 114, and unknown protocol decoder engine 116 described above areprovided to report and enforce policies engine 120 (e.g.,network/routing policies, security policies, and/or firewall policies).For example, firewall policies can be applied to the monitored networktraffic using application identification, user identification, and/orother information to match signatures (e.g., file based, protocol based,and/or other types/forms of signatures for detecting malware orsuspicious behavior).

In some embodiments, firewall 100 also includes a content-ID engine (notshown), and, in some embodiments, the content-ID engine's identifiedcontent is also used by report and enforce policy engine 120, possiblyin various combinations with other information, such as application,user, and/or other information, to enforce various security/firewallpolicies/rules.

In some embodiments, policies are specified using FQDN address objects(e.g., domain names, such as www.google.com or www.yahoo.com, and/orhost/server names, such as MailServer), which are dynamically resolved(e.g., at enforcement time and periodically updated/refreshed) toassociated IP address(es) using various techniques as described hereinwith respect to various embodiments. Thus, policies can be specifiedusing FQDN address objects and enforced using IP addresses along withother criteria, such as port, protocol, and/or othercriteria/information. For example, a policy definition can be specifiedfor security policy enforcement (e.g., firewall, vulnerabilityprotection, anti-malware protection, intrusion prevention, and/or othertypes of security). A policy can also be specified for networking policyenforcement (e.g., policy based forwarding or routing, Quality ofService (QoS), and/or other types of networking policies). In someembodiments, a policy is a collection of rules (e.g., ordered rules).For example, a rule can be specified for ingress/inbound and/oregress/outbound parameters, such as IP address/range/subnet, port,protocol, and/or other characteristics of a network traffic flow. Inaddition to IP address, the rule can be specified by FQDN addressobject(s) of the source and/or destination entities. The actual IPaddresses that will match the rule for policy enforcement can beindependent of policy configuration. As another example, the firewall100 can also monitor the DNS requests and the DNS responses from aclient attempting to resolve names. The firewall can update a cache(e.g., FQDN-IP mapping 118) based on the monitored DNS responses, if theDNS responses are relevant for FQDN resolution of objects used in apolicy (e.g., if the policy uses www.yahoo.com and a client browseraccessed the www.yahoo.com web page, then the firewall can cache the DNSresponse from the DNS server for the DNS request from the browser).

As also shown in FIG. 1, a resolver 120 is provided to perform dynamicFQDN address objects resolution to IP addresses using various techniquesdescribed herein with respect to various embodiments. For example,resolver 120 can send a DNS query to a primary domain name server for aDNS lookup. As another example, one or more servers can be specified forDNS query information requests, in which the servers are used for nameresolution if no specific context based server is configured as furtherdescribed herein with respect to various embodiments. Resolver 120 sendsthe resolved IP address information to FQDN-IP mapping 118, which canstore (e.g., cache or store based on storage limitations and/or otherparameters or configuration settings) the FQDN address object andassociated IP address(es), along with other information, such as TTLparameters/values or configured time-out parameters/values, and possiblyVSYS information as discussed further below with respect to FIG. 3. TheFQDN-IP mapping 118 is shown in communication with policy check 106 andreport and enforce policy 120 (e.g., a policy enforcement engine), whichcan use this information for policy enforcement based on IP addressinformation, in which the policy is specified by FQDN address objects.

In some embodiments, various other functional architectures and flowsare provided to implement the policy enforcement using host informationprofile techniques described herein. For example, some of thesefunctions can be implemented in software executed on a general processorand/or some of these functions can be implemented using hardwareacceleration techniques for faster packet processing of network traffic.

FIG. 2 is a block diagram of a network for dynamic resolution of FQDNaddress objects in policy definitions in accordance with someembodiments. As shown, a data appliance 202 is at the perimeter of aprotected network 210, which includes clients 204, 206, and 208. Dataappliance 202 can include a firewall function, such as firewall function100 as described above, to protect the network and clients within theprotected network 210, which is in communication with the Internet 214and various servers, such as servers 216, 218, and 220 (e.g., webservers, mail servers, file servers, and/or other types of servers).

In some embodiments, data appliance 202 performs a dynamic resolution ofFQDN address objects in policy definitions (e.g., at enforcement time orperiodically updating to maintain a current/fresh IP address resolutionfor such domain names) using various techniques as described herein withrespect to various embodiments. For example, data appliance 202 can senda DNS query to a primary DNS server 212 for a DNS lookup. Thus, policiescan be specified using domain names and/or host/server names andenforced using IP addresses along with other criteria, such as port,protocol, and/or other criteria/information.

FIG. 3 is another block diagram of a network including virtual systems(VSYS) for dynamic resolution of FQDN address objects in policydefinitions in accordance with some embodiments. As shown, a dataappliance 302 is at the perimeter of a protected network 310, whichincludes virtual systems (VSYS) 304 (e.g., for the U.S. network for anenterprise) and VSYS 306 (e.g., for the Asia network for an enterprise).As shown, VSYS-US 304 includes VSYS ENG (e.g., for U.S. engineering)320, and VSYS MKTG (e.g., for U.S. Marketing) 322, and VSYS-ASIA 306includes VSYS ENG (e.g., for Asia engineering) 324, and VSYS MKTG (e.g.,for Asia Marketing) 326. Data appliance 302 can include a firewallfunction, such as firewall function 100 as described above, to protectthe network and clients within the protected network 310, which is incommunication with the Internet 214 (e.g., and various servers, such asservers 216, 218, and 220, as similarly shown in FIG. 2). In someembodiments, a central DNS server/function can be provided and local DNSservers/functions can also be provided for each VSYS. As shown, acentral DNS server 314 is provided for secured/protected network 310,and VSYS-US includes DNS server 316, and VSYS-ASIA 306 includes DNSserver 318.

In some embodiments, data appliance 302 performs a dynamic resolution ofFQDN address objects in policy definitions (e.g., at enforcement time orperiodically updating for maintain a current/fresh IP address resolutionfor such domain names) using various techniques as described herein withrespect to various embodiments. For example, data appliance 302 can senda DNS query to a primary or central DNS server 314 for a DNS lookup. Forexample, one or more central DNS servers can be used for domain nameresolution if no specific context based domain name server is configuredor available.

In some embodiments, a virtual system (VSYS) based DNS configuration canbe used to provide a dynamic resolution of FQDN address objects inpolicy definitions. In some embodiments, data appliance 302 sends a DNSquery to a local VSYS DNS server for a DNS lookup. For example, a DNSserver 316 can be used for DNS queries for VSYS-US 304, and a DNS server318 can be used for DNS queries for VSYS-US 306. In some embodiments, apriority ordered list of DNS services is specified for each instance ofa virtual system (VSYS) configuration. For example, for any nameresolution for traffic flowing through a virtual system, these domainname servers can be queried prior to falling back to system-wide,central domain name server specifications, such as DNS server 314. Insome cases, the same domain name can resolve to different IP addressesbased on VSYS or geography. For example, a host or domain name (e.g.,www.google.com or www.yahoo.com) can resolve to different IP addressesbased on whether the request is from a device based in the U.S. or basedin Asia, as various web sites/web services provide geographically basedweb services to service local requests. As another example, a host nameneed not be fully specified, such as for a mail server, in which casethe MailServer for VSYS ENG 320 will resolve to a different mail serverhost and IP address than the MailServer for VSYS ENG 324.

In some embodiments, a policy (e.g., a security policy and/or networkpolicy) enforced by data appliance 302 is committed to be used by policyenforcer engine implemented by data appliance 302, all the FQDN basedobject entities are resolved to IP addresses. The address resolutioncomponent makes use of the most specific DNS server responses based onthe context in which the FQDN is configured. For example, if the FQDN isconfigured for a virtual system and one or more DNS servers arespecified for that virtual system, such as DNS server 316 for VSYS-US304 and DNS server 318 for VSYS-ASIA 306, then the specific DNS serversare selected for resolving the FQDN entries. The name resolutioncomponent can cache the results as permitted by system memoryavailability for efficiency. In addition, any information regarding Timeto Live (TTL) specified in a DNS response can be stored/cached with theIP address information, such that a fresh/update request can be made toDNS server to update the entry based on the TTL value/parameter. Aperiodic updater (e.g., the resolver function/component or anotherfunction/component) can check the status of each FQDN based entry usedin each policy and re-fetch the resolved IP addresses before the TTLexpires. The update frequency can also be based on a configuredfrequency in addition or in place of the TTL value/parameter. Thisperiodic updater/resolver function/component can also serialize the nameresolution results into non-volatile storage media to promptly recoverfrom a local system and/or software failure. Another configurationelement (e.g., policy enforcement function/component or anotherfunction/component) can specify the system behavior if the nameresolution fails. For example, the action can be to disable the rule orto block traffic until a remedial action is performed (e.g., a change inpolicy definition configuration). The resolver component can continue toperiodically attempt to resolve any unresolved names used in a policy ata configured frequency or a system defined frequency. A list of staticDNS entries can also be configured for a virtual system or for the wholesystem.

In some embodiments, the policy enforcement engine uses an efficientdata structure (e.g., a trie structure) to apply a policy lookup forsource and destination IP address for incoming traffic flow to match apolicy rule. In some embodiments, the policy enforcement engine receivesupdates from a dynamic resolver and adjusts the data structureaccordingly. For example, the policy enforcement engine can apply thenew structure to only new incoming traffic flows or it can also apply toexisting flows as specified by system or configuration element.

In some embodiments, monitored network traffic events are recorded withsource and destination IP address for the flow. For example, such eventscan also optionally include a virtual system (VSYS) identifier ifapplicable. When the events are reported in user interface or reportsand charts, the IP addresses can also be resolved to a domain orhost/server name if available (e.g., based on a name resolution query).The IP address can be resolved in the context of virtual system or thewhole system as similarly discussed above. The resolver can alsocache/store these results in memory for efficiency based on the TTL orconfigured time-out settings for freshness as applicable. These resultscan also be persisted for efficiency.

In some embodiments, multiple data appliances are provided and form aclustered system that can be deployed in active-active or active-passiveconfiguration. As shown in FIG. 3, data appliance 302 is an active dataappliance for protecting network 310, and data appliance 312 is apassive data appliance that can be used, for example, for failoverpurposes. In some embodiments, both data appliances 302 and 312 can bedeployed as active data appliances and perform workload balancing forefficient data traffic monitoring and policy enforcement. In someembodiments, such as for efficiency, the name resolverfunction/component can be activated on a single system (e.g., activedata appliance 302 in an active-passive configuration as shown, or oneof the active data appliances in an active-active configuration). TheFQDN name resolution and period updates are propagated by that dataappliance executing the name resolver to other data appliances in thecluster to keep the information available locally and current/fresh onthose other data appliances in the cluster. In some embodiments,multiple active devices (e.g., multiple data appliances) are provided inan active-active configuration for workload balancing, which can beimplemented using a Virtual Routing Redundancy Protocol (VRRP) and/orother similar techniques.

In some embodiments, the central policy management, shown as centralmanagement 308, is provided for implementing consistent policies acrossmultiple devices deployed in various locations. The rules in the policycan include FQDN entries to specify a client or a server. The samepolicy can also be applied to multiple devices (e.g., data appliance 302and 312 serving various VSYS, such as VSYS 304 and VSYS 306) without anychange. The actual resolution of names to IP addresses is postponeduntil the policy is applied/enforced on a device. On the device, thesame technique noted above will be used to resolve names and theirperiodic updates. Using this approach, the same FQDN entry defined bycentral policy manager 308 can be interpreted appropriately by differentdevices based on their local configuration (e.g., as discussed above, arule applied to the MailServer can be appropriately resolved based onthe relevant VSYS). The central policy can also include different rulesfor different virtual systems (e.g., VSYS ENG can be blocked fromaccessing www.facebook.com, but VSYS MKTG can be allowed to accesswww.facebook.com).

In some embodiments, the traffic flow monitored by an active dataappliance can generate events that are monitored and used for furtheranalysis. For example, the events can be stored in memory and can alsobe stored in persistent storage if required. The traffic flow caninclude both the source and destination IP addresses. In some cases, itis also useful and convenient to report the resolved names for those IPaddresses. The events generated by the devices can be forwarded to acentral repository for storage and aggregation. For context sensitiveresolution of IP addresses to names, the central management candistribute the queries to the reporting device for the event so that thedevice can perform context sensitive name resolution as discussed above.Based on the network topology, it can also be possible to centralize thename resolution on central management system itself. In someembodiments, the central management system/function 308 can activate theresolver function/component to locally look-up/query the deviceconfiguration to select the appropriate DNS server for the device orvirtual system for the device.

FIG. 4 is a block diagram illustrating an architecture for dynamicresolution of FQDN address objects in policy definitions in accordancewith some embodiments. As shown in FIG. 4, client devices 404A, 404B,and 404C are in communication with the Internet 406 via a securitydevice 402. In some embodiments, the security device 402 includes afirewall 412 as shown. In some embodiments, one or more of the clientdevices 404A-404C includes a firewall 414 (e.g., host based firewall) asshown. In some embodiments, the security device 402 includes a dataappliance (e.g., a security appliance), a gateway (e.g., a securityserver), a server (e.g., a server that executes security softwareincluding firewall 412), and/or some other security device, which, forexample, can be implemented using computing hardware, software, orvarious combinations thereof. In some embodiments, firewall 412 and/orfirewall 414 perform some or all of the functions described above withrespect to FIG. 1. For example, client devices 404A-C can includevarious computing devices that can access the Internet via wired and/orwireless communications, such as computer, laptops, tablets, smartphones, and/or various other types of computing devices with networkcommunication capabilities. As also shown, servers 408A-C are incommunication with the Internet 406. For example, a client device canaccess a service provided by a server via the Internet, such as a webrelated service (e.g., web site, cloud based services, streamingservices, or email service), peer-to-peer related service (e.g., filesharing), IRC service (e.g., chat service), and/or any other servicethat can be delivered via the Internet.

In some embodiments, dynamic resolution of FQDN address objects inpolicy definitions is implemented on or integrated into the securityappliance/gateway/server 402 and/or firewall 414. In some embodiments,dynamic resolution of FQDN address objects in policy definitions isimplemented on or integrated into and/or assisted by the security cloudservice 410. For example, the security device 402 (e.g., an integratedsecurity appliance/gateway/server) can communicate with security cloudservice 410 (e.g., using secure communications, such as encryptedcommunication techniques) to receive security related content updates(e.g., signatures, heuristics, application ID related information, userID related information, content ID related information,trusted/untrusted zone information, and/or policy/rules). As anotherexample, the security device 402 (e.g., an integrated securityappliance/gateway/server) can communicate with security cloud service410 (e.g., using secure communications, such as encrypted communicationtechniques) to receive dynamic resolution/updates of FQDN addressobjects in policy definitions (e.g., for system wide IP addressinformation, such as for remote web sites). As will now be apparent,some or all of the functions described above with respect to FIG. 1 canbe assisted by or implemented in whole or in part by the security cloudservice 410. The security cloud service 410 can, for example, reduce theprocessing on the client device (e.g., 404B) and/or security device 402.

FIG. 5 is a functional diagram of hardware components of a dataappliance for dynamic resolution of FQDN address objects in policydefinitions in accordance with some embodiments. The example shown is arepresentation of physical components that can be included in dataappliance 402 (e.g., a data appliance or gateway). Specifically, dataappliance 402 includes a high performance multi-core CPU 502 and RAM504. Data appliance 402 also includes a storage 510 (e.g., one or morehard disks or solid state storage units), which is used to store policyand other configuration information as well as signatures. In someembodiments, storage 510 stores tables that include FQDN address objectsand associated IP addresses and TTL parameters/values and possibly otherinformation. In some cases, a domain or host/server name can havemultiple associated IP addresses. Data appliance 402 can also includeone or more optional hardware accelerators. For example, data appliance402 can include a cryptographic engine 506 configured to performencryption and decryption operations, and one or more FPGAs 508configured to perform signature matching, act as network processors,and/or perform other tasks.

FIG. 6 is a functional diagram of logical components of a data appliancefor dynamic resolution of FQDN address objects in policy definitions inaccordance with some embodiments. The example shown is a representationof logical components that can be included in data appliance 402. Asshown, data appliance 402 includes a management plane 602 and a dataplane 604. In some embodiments, the management plane is responsible formanaging user interactions, such as by providing a user interface forconfiguring policies and viewing log data. The data plane is responsiblefor managing data, such as by performing packet processing and sessionhandling.

Suppose a client 404A attempts to access a server 408B using anencrypted session protocol, such as SSL. Network processor 606 isconfigured to receive packets from client 404A, and provide the packetsto data plane 604 for processing. Flow 608 identifies the packets asbeing part of a new session and creates a new session flow. Subsequentpackets will be identified as belonging to the session based on a flowlookup. If applicable, SSL decryption is applied by SSL decrypter 610.Otherwise, processing by SSL decrypter 610 is omitted. Applicationidentification module 612 is configured to determine what type oftraffic the session involves and to identify a user associated with thetraffic flow. For example, application identification module 612 canrecognize a GET request in the received data and conclude that thesession requires an HTTP decoder. For each type of protocol, thereexists a corresponding decoder 614. In some embodiments, the applicationidentification is performed by an application identification module(e.g., APP-ID engine), and a user identification is performed by anotherfunction/engine. Based on the determination made by applicationidentification module 612, the packets are sent to an appropriatedecoder 614. Decoder 614 is configured to assemble packets (e.g., whichmay be received out of order) into the correct order, performtokenization, and extract out information. Decoder 614 also performssignature matching to determine what should happen to the packet. Asalso shown, signatures 618 are received and stored in the managementplane 602. In some embodiments, policy enforcement (e.g., policies caninclude one or more rules, which can be specified using domain and/orhost/server names, and rules can apply one or more signatures or othermatching criteria or heuristics) using signatures are applied asdescribed herein with respect to various embodiments based on themonitored, identified, and decoded session traffic flows.

As also shown, resolver 618 is provided in the management plane 602 ofthe data appliance 402. In some embodiments, resolver 618 performsdynamic resolution of FQDN address objects (e.g., domain names, such aswww.yahoo.com or www.google.com or any other domain name) and stores theIP address information associated with the FQDN address objects, in somecases, along with other information, such as TTL values/parameters, inthe management plane 602. In some embodiments, resolver 618 performsdynamic resolution for FQDN address objects (e.g., domain and/orhost/server names) specified in policies at policy enforcement time asdescribed herein with respect to various embodiments. In someembodiments, resolver 618 periodically performs dynamic resolutionupdates for FQDN address objects (e.g., domain and/or host/server names)specified in policies at various other times based on configuration,system, events, TTL parameters/values, and/or other triggers/criteria,as described herein with respect to various embodiments. In someembodiments, policy enforcement (e.g., policies can include one or morerules, and rules can apply one or more signatures or other matchingcriteria or heuristics) using rules that specify one or more FQDNaddress objects (e.g., domain and/or host/server names) are applied asdescribed herein with respect to various embodiments based on themonitored, identified, and decoded network traffic flows.

As also shown, management plane 602 of data appliance 402 includesevents 620. In some embodiments, monitored network traffic events arerecorded with source and destination IP address for the network trafficflow in events data store 620. In some embodiments, the eventinformation is also stored with the FQDN address object(s) (e.g., domainand/or host/server name(s)) and the detected IP address information. Insome embodiments, the event information is also stored with a virtualsystem (VSYS) identifier if the monitored network occurred on aparticular VSYS of the network as applicable. In some embodiments, whenthe events are reported (e.g., presented in a user interface displayoutput, log files, reports, and/or charts), the IP addresses are alsoresolved to a host name if available. In some embodiments, the resolver618 sends a DNS query to a local, or remote, domain name resolutioncomponent/function. In some cases, the IP address can be resolved in thecontext of a virtual system (VSYS) or the whole system as describedabove. The resolver 618 can also cache/store these results in memory forefficiency while abiding by the TTL or configured timeout setting tomaintain the freshness of the FQDN address objects and associated IPaddress information. In some cases, these results can also be persistedfor efficiency.

FIG. 7 is a flow diagram for dynamic resolution of FQDN address objectsin policy definitions in accordance with some embodiments. At 702,network traffic is monitored (e.g., using firewall 100). At 704, anetwork policy that includes a domain or host/server name is received.At 706, IP address information associated with the name (e.g., domain orhost/server name) is periodically updated. At 708, the network policy isenforced using the IP address information associated with the name(e.g., domain or host/server name).

FIG. 8 is another flow diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments. At802, a network policy that includes a domain or host/server name isreceived. At 804, IP address information associated with the name (e.g.,domain or host/server name) is periodically updated. At 806, the networkpolicy is enforced using the IP address information associated with thename (e.g., domain or host/server name). At 808, events based on acontext sensitive resolution of the name are monitored. At 810, eventsbased on network security threats are reported, in which the reportedevents include one or more names (e.g., domain or host/server names)associated with at least one of the network security threats.

FIG. 9 is another flow diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments. At902, a first local DNS lookup for a first VSYS using a first DNS serveris dynamically performed on a first domain and/or host/server name for afirst network policy. At 904, a second local DNS lookup for a secondVSYS using a second DNS server is dynamically performed on a seconddomain and/or host/server name for a second network policy. At 906, IPaddress information associated with the first name (e.g., domain orhost/server name) is periodically updated. At 908, IP addressinformation associated with the second name (e.g., domain or host/servername) is periodically updated.

FIG. 10 is another flow diagram for dynamic resolution of FQDN addressobjects in policy definitions in accordance with some embodiments. At1002, a first local DNS lookup for a first VSYS using a first DNS serveris dynamically performed on a first domain and/or host/server name for afirst network policy using a first security appliance. At 1004, a secondlocal DNS lookup for a second VSYS using a second DNS server isdynamically performed on a second domain and/or host/server name for asecond network policy using the first security appliance. At 1006, IPaddress information associated with the first name (e.g., domain orhost/server name) and the second name (e.g., domain or host/server name)are periodically updated using the first security appliance. At 1008,the resolved/updated IP address information for the first name and thesecond name is periodically sent to a second security appliance. Forexample, the second security appliance can be an active securityappliance or passive security appliance in a cluster (e.g., used forfailover and/or workload balancing as discussed above).

As will now be apparent, various techniques for dynamic resolution ofFQDN address objects in policy definitions techniques can be appliedusing the various embodiments described herein. Also, various system andnetwork architectures can be applied using the various techniquesdescribed herein. For example, various techniques for dynamic resolutionof FQDN address objects in policy definitions as described herein can beimplemented in an integrated security appliance that provides inlinefiltering functionality and also executes the dynamic resolution of FQDNaddress objects in policy definitions techniques as described herein. Asanother example, the dynamic resolution of FQDN address objects inpolicy definitions functionality can be implemented using anotherappliance or computer server, which can communicate to various othersecurity functions (e.g., security appliances, network appliances,and/or host based security software). As yet another example, thedynamic resolution of FQDN address objects in policy definitionsfunctionality can be implemented using or assisted by a security cloudservice, which can communicate to various other security functions(e.g., security appliances, network appliances, and/or host basedsecurity software) and/or generates new security updates (e.g., pushesthe new signature(s) to various security devices/software that subscribeto signature updates from the security cloud service vendor).

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, the invention is not limitedto the details provided. There are many alternative ways of implementingthe invention. The disclosed embodiments are illustrative and notrestrictive.

What is claimed is:
 1. A system, comprising: a processor executinginstructions to: receive a network policy that includes a domain name,wherein the domain name includes a Fully Qualified Domain Name (FQDN);periodically update Internet Protocol (IP) address informationassociated with the domain name by performing a Domain Name Server (DNS)query, wherein the updating of the IP address information comprises:determine whether the domain name has been resolved; in the event thatthe domain name has not been resolved, attempt to resolve the domainname; and in the event that the domain name has been resolved, checkwhether the IP address information associated with the domain name haschanged; and in the event that the IP address information is notupdated, disable or block network traffic associated with the IP addressinformation that is not updated; and a memory coupled to the processorand configured to provide the processor with the instructions withinstructions.
 2. The system recited in claim 1, wherein the systemincludes a security appliance, and wherein the security applianceincludes a firewall.
 3. The system recited in claim 1, wherein the IPaddress information includes Internet Protocol Version 4 (IPv4)information or Internet Protocol Version 6 (IPv6) information.
 4. Thesystem recited in claim 1, wherein the IP address information isperiodically updated based on a Time To Live (TTL) value.
 5. The systemrecited in claim 1, wherein the IP address information is periodicallyupdated based on a system frequency.
 6. The system recited in claim 1,wherein the IP address information is periodically updated based on aconfiguration setting.
 7. The system recited in claim 1, wherein the IPaddress information is periodically updated based on an event.
 8. Thesystem recited in claim 1, wherein the network policy includes a networksecurity rule that is based on the domain name.
 9. The system recited inclaim 1, wherein the network policy includes a network security rulethat is based on the domain name, and wherein the network policyincludes one or more of the following rules based on the domain name: arouting rule, a Quality of Service (QoS) rule, and a workload balancingrule.
 10. The system recited in claim 1, wherein the domain name onlyincludes a subset of the FQDN, and the policy includes a host name thatis not specified as the FQDN.
 11. The system recited in claim 1, whereinthe updating of the IP address information further comprises: execute adynamic resolver, wherein the dynamic resolver performs the periodicallyupdating the IP address information associated with the domain name. 12.The system recited in claim 1, wherein the processor is furtherexecuting instructions to: dynamically perform a resolution of thedomain name from a central policy manager for implementing the networkpolicy based on the domain name for enforcing the network policy basedon the domain name, wherein the domain name was not resolved or updatedprior to enforcing the network policy.
 13. The system recited in claim1, wherein the processor is further executing instructions to: enforcethe network policy based on the IP address, wherein the IP address isassociated with the domain name, and the policy includes a rule oraction based on the domain name.
 14. The system recited in claim 1,wherein the processor is further executing instructions to: enforce thenetwork policy based on the IP address, wherein the IP address isassociated with the domain name, and the policy includes a rule oraction based on the domain name; and monitor events based on a contextsensitive resolution of the domain name.
 15. The system recited in claim1, wherein the processor is further executing instructions to: store thedomain name, the IP address information associated with the domain name,and a Time To Live (TTL) value for the IP address information associatedwith the domain name.
 16. The system recited in claim 1, wherein theprocessor is further executing instructions to: store the domain name, aplurality of IP addresses associated with the domain name, and a Time ToLive (TTL) value for each of the IP addresses associated with the domainname in a data store including one or more tables.
 17. The systemrecited in claim 1, wherein the processor is further executinginstructions to: report events based on network security threats,wherein the reported events include one or more domain names associatedwith at least one of the network security threats.
 18. The systemrecited in claim 1, wherein the processor is further executinginstructions to: dynamically update the IP address information atenforcement time.
 19. A method, comprising: receiving a network policythat includes a domain name, wherein the domain name includes a FullyQualified Domain Name (FQDN); periodically updating Internet Protocol(IP) address information associated with the domain name by performing aDomain Name Server (DNS) query to a DNS server, wherein the updating ofthe IP address information comprises: determining whether the domainname has been resolved using a processor executing instructions; in theevent that the domain name has not been resolved, attempting to resolvethe domain name using the processor executing instructions; and in theevent that the domain name has been resolved, checking whether the IPaddress information associated with the domain name has changed usingthe processor executing instructions; and in the event that the IPaddress information is not updated, disabling or blocking networktraffic associated with the IP address information that is not updatedusing the processor executing instructions.
 20. A computer programproduct, the computer program product being embodied in a non-transitorycomputer readable storage medium and comprising computer instructionsfor: receiving a network policy that includes a domain name, wherein thedomain name includes a Fully Qualified Domain Name (FQDN); periodicallyupdating Internet Protocol (IP) address information associated with thedomain name by performing a Domain Name Server (DNS) query, wherein theupdating of the IP address information comprises: determining whetherthe domain name has been resolved; in the event that the domain name hasnot been resolved, attempting to resolve the domain name; and in theevent that the domain name has been resolved, checking whether the IPaddress information associated with the domain name has changed; and inthe event that the IP address information is not updated, disabling orblocking network traffic associated with the IP address information thatis not updated.
 21. The method of claim 19, wherein the IP addressinformation includes Internet Protocol Version 4 (IPv4) information orInternet Protocol Version 6 (IPv6) information.
 22. The method of claim19, wherein the IP address information is periodically updated based ona Time To Live (TTL) value, a system frequency, a configuration setting,or an event.
 23. The method of claim 19, wherein the network policyincludes a network security rule that is based on the domain name, andwherein the network policy includes one or more of the following rulesbased on the domain name: a routing rule, a Quality of Service (QoS)rule, and a workload balancing rule.
 24. The method of claim 19, whereinthe domain name only includes a subset of the FQDN, and the policyincludes a host name that is not specified as the FQDN.
 25. The methodof claim 19, further comprising: dynamically performing a resolution ofthe domain name from a central policy manager for implementing thenetwork policy based on the domain name for enforcing the network policybased on the domain name, wherein the domain name was not resolved orupdated prior to enforcing the network policy.
 26. The method of claim19, further comprising: enforcing the network policy based on the IPaddress, wherein the IP address is associated with the domain name, andthe policy includes a rule or action based on the domain name.
 27. Themethod of claim 19, further comprising: enforcing the network policybased on the IP address, wherein the IP address is associated with thedomain name, and the policy includes a rule or action based on thedomain name; and monitoring events based on a context sensitiveresolution of the domain name.
 28. The method of claim 19, furthercomprising: storing the domain name, a plurality of IP addressesassociated with the domain name, and a Time To Live (TTL) value for eachof the IP addresses associated with the domain name in a data storeincluding one or more tables.
 29. The method of claim 19, furthercomprising: reporting events based on network security threats, whereinthe reported events include one or more domain names associated with atleast one of the network security threats.
 30. The method of claim 19,further comprising: dynamically updating the IP address information atenforcement time.
 31. The computer program product recited in claim 20,wherein the IP address information includes Internet Protocol Version 4(IPv4) information or Internet Protocol Version 6 (IPv6) information.32. The computer program product recited in claim 20, wherein the IPaddress information is periodically updated based on a Time To Live(TTL) value, a system frequency, a configuration setting, or an event.33. The computer program product recited in claim 20, wherein thenetwork policy includes a network security rule that is based on thedomain name, and wherein the network policy includes one or more of thefollowing rules based on the domain name: a routing rule, a Quality ofService (QoS) rule, and a workload balancing rule.
 34. The computerprogram product recited in claim 20, wherein the domain name onlyincludes a subset of the FQDN, and the policy includes a host name thatis not specified as the FQDN.
 35. The computer program product recitedin claim 20, further comprising: dynamically performing a resolution ofthe domain name from a central policy manager for implementing thenetwork policy based on the domain name for enforcing the network policybased on the domain name, wherein the domain name was not resolved orupdated prior to enforcing the network policy.
 36. The computer programproduct recited in claim 20, further comprising: enforcing the networkpolicy based on the IP address, wherein the IP address is associatedwith the domain name, and the policy includes a rule or action based onthe domain name.
 37. The computer program product recited in claim 20,further comprising: enforcing the network policy based on the IPaddress, wherein the IP address is associated with the domain name, andthe policy includes a rule or action based on the domain name; andmonitoring events based on a context sensitive resolution of the domainname.
 38. The computer program product recited in claim 20, furthercomprising: storing the domain name, a plurality of IP addressesassociated with the domain name, and a Time To Live (TTL) value for eachof the IP addresses associated with the domain name in a data storeincluding one or more tables.
 39. The computer program product recitedin claim 20, further comprising: reporting events based on networksecurity threats, wherein the reported events include one or more domainnames associated with at least one of the network security threats. 40.The computer program product recited in claim 20, further comprising:dynamically updating the IP address information at enforcement time.